Chevrolet Repair: no gas coming to fuel pump, electric fuel pump, chevy caprice

Question
QUESTION: i just installed a fuel pump on my 1970 chevy caprice 454 eng, i made sure the pin inside block would come down onto the pump. i have no gas coming threw my pump to my carburetor, i know that cuz i disconnect the gas line from car to pump, then felt 4 air suction on pump and it don't suck air. i sucked air threw the gas line and gas came out..i put gas in the carburetor and it starts up but dies when gas empties.. do U know what my problem can be? or should i switch it from a manual pump to electric
ANSWER: Is it a new fuel pump that you installed?


---------- FOLLOW-UP ----------

QUESTION: yes, today i checked rubber line from gas tank, thats fine. I checked the gas pump connection 1 more time thats fine. it makes a whistle sound when U push pump in like it supposed to.  

Answer
Make sure the pin is on the pump arm and make sure the pump arm is the same length as the old pump. If it is then return the pump to the parts store. I wouldnt suggest moving to a electric fuel pump. Nothing wrong with moving to a electric pump but I would personally stay with the current setup.
Oh yeah, I forgot, I am not trying to insult you but feel I have to ask you if there is fuel in the tank.